In many circumstances it would be useful to determine if a device that utilizes ultraviolet wavelengths, visible wavelengths, or infrared wavelengths, such as a sniper scope, a pair of binoculars, field glasses, monoculars, a digital camera, a video recorder, a sight of a weapon, or the like, referred to herein as a “threat optic,” is surveilling a location. Reflections from manmade surfaces can sometimes be detected by a camera, but not all manmade surfaces constitute a threat. Thus, distinguishing reflections from a potentially dangerous object, such as a threat optic, and reflections from background clutter reflectors, such as bottles, cans, headlights, and other reflective surfaces, would be useful.